Many different types of honing mandrels and other honing devices have been designed and manufactured in the past for a wide variety of uses and applications. There also exists numerous designs and constructions of honing mandrels having abrasive assemblies mounted thereon which are adjustable during a honing operation, some of these mandrels utilize single radially adjustable abrasive assemblies while others utilize a plurality of circumferentially spaced abrasive assemblies, one or more of which are radially adjustable during a honing operation to maintain the abrasive assemblies in contact under pressure with a work surface being honed. Typical of the known adjustable honing mandrels and the known abrasive assembly movement means are the constructions shown and disclosed in Sunnen U.S. Pat. Nos. Re 18,763; 1,902,194; 1,904,336; 1,946,041; 1,982,836; 2,040,281; 2,815,615 and 3,378,962.
It has also been common practice in the past to construct honing mandrels having body portions with a central pinion gear rotatably mounted therein, and wherein a plurality of work engaging assemblies are mounted for radial movement on the mandrel body. These mandrel constructions include rack gear portions or pin members which cooperatively engage pinion gears or radial pins and work engaging portions which engage the work surface to be honed. In such prior art constructions, all of the work engaging assemblies are moved radially outwardly at the same rate. Typical of such constructions are the constructions shown and disclosed in Sunnen U.S. Pat. Nos. 3,378,962 and 4,524,549. None of the known prior art honing mandrel constructions which are adjustable during a honing operation utilize an expander member or wedge assembly which moves within a tubular member to uniformly increase the diameter of the tool over its entire length.
Honing tool constructions which utilize an expander member or wedge assembly for increasing the diameter of the mandrel are typically associated with single pass through honing mandrels. With known single pass through devices, it has not been possible to change the honing diameter of such devices during a honing operation but only to preset the honing diameter prior to the honing operation to establish the desired stock removal. For this reason, known single pass through mandrels, and especially those that use super abrasive materials such as abrasives that include diamond particles, particles of cubic boron nitride and other like hard materials, have been tapered over most of their length to control the amount of material that can be removed from the workpiece to establish a desired diameter and work surface smoothness. No adjustment of the honing diameter is possible during honing when using known single pass through honing devices, and this has greatly limited their usefulness and has substantially reduced the amount of stock that can be removed from a work surface. Typical of such known single pass through honing tool constructions are the constructions shown and disclosed in Althen U.S. Pat. Nos. 4,197,680 and 4,253,279.
The present honing mandrel constructions, unlike the known single pass through honing devices, are specifically designed for multi-stroke honing applications and each includes a honing surface which is substantially cylindrical, preferably not tapered, along its length. Also, importantly, each of the present mandrel constructions, unlike the known in-process adjustable mandrel constructions, provide for relative axial movement between a tubular honing member and an expander member or wedge assembly during a honing operation so as to uniformly change the honing diameter of such tool along its length. This enables a user to achieve a more uniform and more accurately honed work surface with a much greater range of honing diameter adjustability as compared to the known prior art constructions and especially single pass devices. These features in a honing tool represent an important advancement in the honing art as will be hereinafter explained.